Ship every product decision with evidence behind it.
Run experiments, manage feature flags, and let your data warehouse do the heavy lifting—with statistical defaults built on 15 years of operating evidence. Proven at Spotify. Now yours.
Everything you need
to experiment and grow
Watches sessions, experiments, tells you what's next.
Battle-tested for the last decade at Spotify
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See the latest from Confidence
Accurate Sample Size for Always-Valid Inference
Most A/B testing tools either overestimate the sample size needed for always-valid inference or do not adjust for the sequential test in the sample size calculation at all. We derived a closed-form correction that requires no simulation.
When A/B tests tell you what you want to hear
A/B testing maturity has a dangerous middle phase: teams test, dislike the answer, and explain it away. How to spot it and learn to trust your data.
When AI writes the code, who decides what ships?
AI-accelerated code production increases the need for experimentation. The validation bottleneck grows with build speed. The fastest learners will win.
What Makes a Good Sample Size Calculator?
A good sample size calculator must match your analysis: sequential testing, multiple metrics, and variance reduction all change the number it returns.
The Judgment Gap
AI made building cheap. It also made bad decisions cheaper to ship. The distance between execution speed and validation speed is the judgment gap.